python 字符串 变量
Python | 检查变量是否为字符串 (Python | Check if a variable is a string)
To check whether a defined variable is a string type or not, we can use two functions which are Python library functions,
要检查定义的变量是否为字符串类型，我们可以使用两个函数，它们是Python库函数，
Using isinstance()
使用isinstance()
Using type()
使用type()
1)使用isinstance()函数检查变量是否为字符串 (1) Checking a variable is a string or not using isinstance() function)
isinstance() function accepts two parameters – 1) variable name (object) and 2) data type (class) and returns whether an object is an instance of a class or of a subclass thereof.
isinstance()函数接受两个参数– 1)变量名( 对象 )和2)数据类型( 类 )，并返回对象是类的实例还是其子类的实例。
Syntax:
句法：
isinstance(obj, class_or_tuple)
Example:
例：
# variables
a = 100 # an integer variable
b = 10.23 # a float variable
c = 'A' # a character variable
d = 'Hello' # a string variable
e = "Hello" # a string variable
# checking types
if isinstance(a, str):
print("Variable \'a\' is a type of string.")
else:
print("Variable \'a\' is not a type of string.")
if isinstance(b, str):
print("Variable \'b\' is a type of string.")
else:
print("Variable \'b\' is not a type of string.")
if isinstance(c, str):
print("Variable \'c\' is a type of string.")
else:
print("Variable \'c\' is not a type of string.")
if isinstance(d, str):
print("Variable \'d\' is a type of string.")
else:
print("Variable \'d\' is not a type of string.")
if isinstance(e, str):
print("Variable \'e\' is a type of string.")
else:
print("Variable \'e\' is not a type of string.")
Output
输出量
Variable 'a' is not a type of string.
Variable 'b' is not a type of string.
Variable 'c' is a type of string.
Variable 'd' is a type of string.
Variable 'e' is a type of string.
2)使用type()函数检查变量是否为字符串 (2) Checking a variable is string using type() function)
type() function accepts one parameter (others are optional), and returns its type.
type()函数接受一个参数(其他参数是可选的)，并返回其类型。
Syntax:
句法：
type(object)
Example:
例：
# variables
a = 100 # an integer variable
b = 10.23 # a float variable
c = 'A' # a character variable
d = 'Hello' # a string variable
e = "Hello" # a string variable
# checking types
if type(a) == str:
print("Variable \'a\' is a type of string.")
else:
print("Variable \'a\' is not a type of string.")
if type(b) == str:
print("Variable \'b\' is a type of string.")
else:
print("Variable \'b\' is not a type of string.")
if type(c) == str:
print("Variable \'c\' is a type of string.")
else:
print("Variable \'c\' is not a type of string.")
if type(d) == str:
print("Variable \'d\' is a type of string.")
else:
print("Variable \'d\' is not a type of string.")
if type(e) == str:
print("Variable \'e\' is a type of string.")
else:
print("Variable \'e\' is not a type of string.")
Output
输出量
Variable 'a' is not a type of string.
Variable 'b' is not a type of string.
Variable 'c' is a type of string.
Variable 'd' is a type of string.
Variable 'e' is a type of string.
翻译自: https://www.includehelp.com/python/check-whether-a-variable-is-a-string-or-not.aspx
python 字符串 变量
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